In recent years, semiconductor modules using nonvolatile memories have been used for a memory media in various types of information terminal equipments.
As a component of the semiconductor module, a controller is necessary for controlling the nonvolatile memory, and associated devices. In comparison with the nonvolatile memory, the controller has a higher heat generation rate during operation. Because of the higher heat generation rate, a lot of the heat generated by the controller spread and are held within the semiconductor module. This heat increases the module temperature and may lead to temperature related mis-operation of the nonvolatile memory.
In order to reduce the effect of the controller generated heat on the memory portion, a semiconductor module in which a plurality of nonvolatile memory devices are arranged on one or both surfaces of a substrate and a controller chip arranged at a peripheral part of the substrate has been proposed. As a result, the memory devices are generally remotely located on the underlying substrate, from the controller and from the heat generated thereby. This layout has been adopted in conventional semiconductor modules.
In addition, a ball grid array package in which a controller chip and the nonvolatile memory chip are formed and to which wire bonding and mold sealing are applied has been proposed.
Further, as the capacity of the memory devices increases, faster read, write, and erase operations of the memory devices is required. However, the greater the physical distance between the controller and memory devices, the slower the rate of instructions from the controller to the memory device.
Thus, there is a need to control or otherwise reduce the effect of the heat generated by the controller while operating the memory devices at a high speed and with a high precision.